[time-nuts] "Antelope Audio Launches The Isochrone 10M Affordable Atomic Clocking Device"

[Magnus Danielson]

From: David Forbes <dforbes at dakotacom.net>
Subject: Re: [time-nuts] "Antelope Audio Launches The Isochrone 10M Affordable Atomic Clocking Device"
Date: Thu, 19 Apr 2007 09:38:25 -0700
Message-ID: <a06240503c24d4a024267@[192.168.0.24]>

> The only thing missing from that expensive box is a 12 digit 
> frequency display to show all the zeroes that the customer just paid 
> so much money for.
> 
> An accurate clock is somewhat useful, but the audiophile way is to 
> spend a lot of money to optimize some unimportant parameter way too 
> far while ignoring the basic things.
> 
> Considering that only rarely is a recording more than an hour long, 
> having sample timing accuracy for an eight-day-long recording is 
> overkill.

Certainly.

> Also, it's hard to find a person capable of detecting the pitch error 
> caused by any crystal oscillator being out of whack by the typical 
> .01% of a cheap microprocessor crystal. That's less than a tenth of a 
> Hertz at middle A!

Modulations up to about a minute is what you care about at the most.
Also, if you record with propper time is one thing, but do you actually play
it with that? Where is that MP3 player or CD-player with 10 MHz input?

> However, if you want the best for your mastering studio, a $100 ebay 
> surplus ovenized crystal will get you to .00001% accuracy easily, 
> with lower jitter than a phase-locked rubidium oscillator.

It will be more than sufficient, by far.

The trouble is that you want something which renders you the sample rate
(multiple) with low enought jitter. A low jitter reference crystal does you
no good if you resynthesize it into a noisy 192 kHz, since the high frequency
noise comes from the locked oscillator.

Cheers,
Magnus